A 1988 patent to Wheeler, U.S. Pat. No. 4,717,930, discloses a camera using instant photography techniques which incorporates a transparent template mounted in alignment with the exposure opening of a film cassette inserted into the camera. The template includes indicia which is recorded on each successive film unit as the normal exposure cycle occurs.
Additionally, the Wheeler patent discloses a solid transparent body secured to the front of the camera housing and overlying the camera's strobe or flash unit, view finder, and lens opening. The body is of clear transparent plastic material such as LUCITE. An oval aperture in the body is aligned with the lens opening of the camera whereby light generated by the flash unit and reflected from the object being photographed passes directly through the aperture to the lens opening. The patent discloses that the aperture is preferably elliptical in shape.
On the other hand, some of the light from the flash unit is reflected one or more times by the surfaces of the plastic body until it arrives at the elliptical surface of the aperture through the body. The elliptical surface allows some of the light to pass as diffused light through the aperture and into the lens opening in the camera. This diffused light results in a lightening or washing out of the area of the film unit surrounding the photographed object, tending to make the background in the film unit generally white except for the shape of the aperture through the plastic body and the indicia on the template.
The disclosed template in the film cassette and the diffused light combine to expose the periphery of the film unit in the cassette and produce an image of the indicia of the template on a white background which surrounds the elliptical shape encompassing the object being photographed.
The light modulated, white or near white, background produced by the reflected diffused light from the plastic body emphasizes the indicia from the template and the object being photographed.
Unfortunately, as disclosed in the Wheeler patent, the plastic body to be affixed to the front face of the camera housing is heavy and the attaching mechanism results in a heavy, unbalanced camera.
Placing templates in alignment with the exposure opening of the film cassettes for purposes of having a particular indicia on each successive film frame is known. Examples are disclosed in commonly owned, copending, patent application Ser. No. 620,897, filed Dec. 3, 1990 now U.S. Pat. No. 5,144,348.